7. Project Summary/Abstract Large, persistent racial disparities in preterm delivery (PTD) exist, with African Americans (AAs) having higher rates than Non-Hispanic whites. Since traditional risk factors do not fully account for this disparity, other explanations must be identified. Residential environment may be an important risk factor for adverse birth outcomes, given the strikingly different neighborhoods in which AA and white women reside, and the resulting racial disparity in exposures to social determinants of health. Some aspects of residential environment have been linked to adverse birth outcomes, including PTD, however the existing studies have only defined neighborhood exposures using aggregate data from the US Census, which is unable to identify aspects of residential environment may be detrimental. Recent evidence suggests that subjective assessments of neighborhoods from residents may be able to provide unique contextual information not available in Census data, including social environment. Therefore, the current study seeks to examine the links between objective and perceived physical and social residential environment and PTD among AA women from the Life-course Influences on Fetal Environments (LIFE) study, with the following specific aims: (1) to examine measurement of subjective neighborhood constructs, including methodological properties of subjective assessments, (2) to determine the associations between perceived social and physical environment and prevalence of PTD, and (3) to examine the links between objective physical environment and PTD using multilevel modeling. This research will extend the current knowledge of neighborhood effects on PTD in several critical ways: (1) by comparing objective and subjective measures of residential environment, (2) by determining whether objective neighborhood measures affect perceptions of neighborhood, and (3) by conducting research in a cohort comprised entirely of AA women, a group known to suffer disproportionately from PTD. If aspects of the physical and social residential environment are associated with PTD among AAs, this knowledge can inform future intervention studies as well as policy efforts focused on eliminating adverse features of neighborhoods. The proposed fellowship will provide the rigorous training necessary for the applicant to become an independent investigator who will devote her career to identifying causes of the enduring racial disparities in PTD, with a particular focus on neighborhoods.